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OpenFOAM-12/src/parallel/decompose/decompositionMethods/structuredDecomp/structuredDecomp.C
Henry Weller f97f6326f0 Decomposition/redistribution: Separated choice of mesh decomposition and redistribution methods
When snappyHexMesh is run in parallel it re-balances the mesh during refinement
and layer addition by redistribution which requires a decomposition method
that operates in parallel, e.g. hierachical or ptscotch.  decomposePar uses a
decomposition method which operates in serial e.g. hierachical but NOT
ptscotch.  In order to run decomposePar followed by snappyHexMesh in parallel it
has been necessary to change the method specified in decomposeParDict but now
this is avoided by separately specifying the decomposition and distribution
methods, e.g. in the incompressible/simpleFoam/motorBike case:

numberOfSubdomains  6;

decomposer      hierarchical;
distributor     ptscotch;

hierarchicalCoeffs
{
    n               (3 2 1);
    order           xyz;
}

The distributor entry is also used for run-time mesh redistribution, e.g. in the
multiphase/interFoam/RAS/floatingObject case re-distribution for load-balancing
is enabled in constant/dynamicMeshDict:

distributor
{
    type            distributor;

    libs            ("libfvMeshDistributors.so");

    redistributionInterval  10;
}

which uses the distributor specified in system/decomposeParDict:

distributor     hierarchical;

This rationalisation provides the structure for development of mesh
redistribution and load-balancing.
2021-12-15 22:12:00 +00:00

185 lines
5.2 KiB
C++

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Copyright (C) 2011-2021 OpenFOAM Foundation
\\/ M anipulation |
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License
This file is part of OpenFOAM.
OpenFOAM is free software: you can redistribute it and/or modify it
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(at your option) any later version.
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
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\*---------------------------------------------------------------------------*/
#include "structuredDecomp.H"
#include "addToRunTimeSelectionTable.H"
#include "FaceCellWave.H"
#include "topoDistanceData.H"
#include "fvMeshSubset.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
namespace Foam
{
defineTypeNameAndDebug(structuredDecomp, 0);
addToRunTimeSelectionTable
(
decompositionMethod,
structuredDecomp,
decomposer
);
addToRunTimeSelectionTable
(
decompositionMethod,
structuredDecomp,
distributor
);
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::structuredDecomp::structuredDecomp(const dictionary& decompositionDict)
:
decompositionMethod(decompositionDict),
methodDict_(decompositionDict_.optionalSubDict(typeName + "Coeffs")),
patches_(methodDict_.lookup("patches"))
{
methodDict_.set("numberOfSubdomains", nDomains());
method_ = decompositionMethod::NewDecomposer(methodDict_);
}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
Foam::labelList Foam::structuredDecomp::decompose
(
const polyMesh& mesh,
const pointField& cc,
const scalarField& cWeights
)
{
const polyBoundaryMesh& pbm = mesh.boundaryMesh();
const labelHashSet patchIDs(pbm.patchSet(patches_));
label nFaces = 0;
forAllConstIter(labelHashSet, patchIDs, iter)
{
nFaces += pbm[iter.key()].size();
}
// Extract a submesh.
labelHashSet patchCells(2*nFaces);
forAllConstIter(labelHashSet, patchIDs, iter)
{
const labelUList& fc = pbm[iter.key()].faceCells();
forAll(fc, i)
{
patchCells.insert(fc[i]);
}
}
// Subset the layer of cells next to the patch
fvMeshSubset subsetter(dynamic_cast<const fvMesh&>(mesh));
subsetter.setLargeCellSubset(patchCells);
const fvMesh& subMesh = subsetter.subMesh();
pointField subCc(cc, subsetter.cellMap());
scalarField subWeights(cWeights, subsetter.cellMap());
// Decompose the layer of cells
labelList subDecomp(method_().decompose(subMesh, subCc, subWeights));
// Transfer to final decomposition
labelList finalDecomp(cc.size(), -1);
forAll(subDecomp, i)
{
finalDecomp[subsetter.cellMap()[i]] = subDecomp[i];
}
// Field on cells and faces.
List<topoDistanceData> cellData(mesh.nCells());
List<topoDistanceData> faceData(mesh.nFaces());
// Start of changes
labelList patchFaces(nFaces);
List<topoDistanceData> patchData(nFaces);
nFaces = 0;
forAllConstIter(labelHashSet, patchIDs, iter)
{
const polyPatch& pp = pbm[iter.key()];
const labelUList& fc = pp.faceCells();
forAll(fc, i)
{
patchFaces[nFaces] = pp.start()+i;
patchData[nFaces] = topoDistanceData(finalDecomp[fc[i]], 0);
nFaces++;
}
}
// Propagate information inwards
FaceCellWave<topoDistanceData> deltaCalc
(
mesh,
patchFaces,
patchData,
faceData,
cellData,
mesh.globalData().nTotalCells()+1
);
// And extract
bool haveWarned = false;
forAll(finalDecomp, celli)
{
if (!cellData[celli].valid(deltaCalc.data()))
{
if (!haveWarned)
{
WarningInFunction
<< "Did not visit some cells, e.g. cell " << celli
<< " at " << mesh.cellCentres()[celli] << endl
<< "Assigning these cells to domain 0." << endl;
haveWarned = true;
}
finalDecomp[celli] = 0;
}
else
{
finalDecomp[celli] = cellData[celli].data();
}
}
return finalDecomp;
}
Foam::labelList Foam::structuredDecomp::decompose
(
const labelListList& globalPointPoints,
const pointField& points,
const scalarField& pointWeights
)
{
NotImplemented;
return labelList::null();
}
// ************************************************************************* //